Evidence for Heavy Hyperhydrogen<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mmultiscripts><mml:mi mathvariant="normal">H</mml:mi><mml:mprescripts /><mml:mi>Λ</mml:mi><mml:mn>6</mml:mn></mml:mmultiscripts></mml:math>
Evidence for Heavy Hyperhydrogen<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mmultiscripts><mml:mi mathvariant="normal">H</mml:mi><mml:mprescripts /><mml:mi>Λ</mml:mi><mml:mn>6</mml:mn></mml:mmultiscripts></mml:math>
Evidence for the neutron-rich hypernucleus $_{\ensuremath{\Lambda}}^{6}\mathrm{H}$ is presented from the FINUDA experiment at $\mathrm{DA}\ensuremath{\Phi}\mathrm{NE}$, Frascati, studying $({\ensuremath{\pi}}^{+},{\ensuremath{\pi}}^{\ensuremath{-}})$ pairs in coincidence from the ${K}_{\mathrm{stop}}^{\ensuremath{-}}+^{6}\mathrm{Li}\ensuremath{\rightarrow}_{\ensuremath{\Lambda}}^{6}\mathrm{H}+{\ensuremath{\pi}}^{+}$ production reaction followed by $_{\ensuremath{\Lambda}}^{6}\mathrm{H}\ensuremath{\rightarrow}^{6}\mathrm{He}+{\ensuremath{\pi}}^{\ensuremath{-}}$ weak decay. The production rate of $_{\ensuremath{\Lambda}}^{6}\mathrm{H}$ undergoing this two-body ${\ensuremath{\pi}}^{\ensuremath{-}}$ decay is determined to be $(2.9\ifmmode\pm\else\textpm\fi{}2.0)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}/{K}_{\mathrm{stop}}^{\ensuremath{-}}$. Its binding energy, evaluated jointly …